Process for the production of lyophilized liver extract

ABSTRACT

LYOPHILIZED PHARMACEUTICAL COMPOSITIONS WHICH DISSOLVE RAPIDLY IN WATER WHILE HAVING IMPROVED MECHANICAL STRENGTH AND RESISTANCE TO ATMOSPHERIC MOISTURE ARE MADE BY LYOPHILIZING MEDICAMENTS IN AQUEOUS ADMIXTURE WITH A CRYSTALLIZABLE EXTENDER AND A WATER SOLUBLE COLLOID.

United States Patent 3,778,510 PROCESS FOR THE PRODUCTION OF LYOPHILIZED LIVER EXTRACT Pierre Blonde, Avenue Noel, 19 bis, Saint-Maur-des-Fosses, France No Drawing. Continuation of abandoned application Ser. No. 28,550, Apr. 14, 1970. This application Aug. 22, 1972, Ser. No. 282,832 Claims priority, application France, Apr. 15, 1969, 6911589; Mar. 24, 1970, 7010548 Int. Cl. A61k 17/00 US. Cl. 424-106 2 Claims ABSTRACT OF THE DISCLOSURE Lyophilized pharmaceutical compositions which dissolve rapidly in water while having improved mechanical strength and resistance to atomspheric moisture are made by lyophilizing medicaments in aqueous admixture with a crystallizable extender and a water soluble colloid.

This is a continuation of application Ser. No. 28,550 filed Apr. 14, 1970, now abandoned.

This invention relates to the production of pharmaceutical compositions.

It is well known that lyophilised products always have a fragile structure and are furthermore generally extremely hygroscopic. These two properties make them difficult to handle in an environment of normal humidity and make it necessary to use perfectly sealed packages for them.

This invention provides a process for the production of pharmaceutical compositions which have been dehydrated or desolvated by lyophilisation, and which are capable either of resuming their original form if solvent is provided, or of dissolving rapidly and completely in water. The new process furthermore makes it possible to lessen the two disadvantages described above by combining the medicament to be lyophilised with a lyophilisation adjuvant which imparts improved mechanical strength to the lyophilised product and slows down the moisture uptake.

The process of the present invention comprises mixing a medicament, in the presence of water with at least one lyophilisation adjuvant chosen from:

(a) non-toxic colloids, polysaccharides and polymers of high molecular weight capable of yielding colloidal solutions, and (b) soluble, edible, crystallisable, extenders, and lyophilising the mixture obtained.

The lyophilisation adjuvants used in the new process must have such physical properties that their addition cannot interfere with the proper course of the lyophilization operation. Thus, they must not lower the freezing point of the material to be lyophilised to a level where melting would occur during the lyophilization. As these substances must be considered to be excipients for the pharmaceutical compositions, it is essential for them to have no effect on the medicament and to be physiologically innocuous.

Suitable materials are: (a) colloids, polysaccharides of high molecular weight, and high polymers which can yield colloidal solutions, especially gum arabic, alginates and pectinates, polyvinylpyrrolidone, polyethylene 'glycols, and carboxymethylcellulose; and (b) soluble, edible and crystallisable extenders, especially lactose, glycine, mannitol, sorbitol, glucose, and sucrose. Amongst the latter lactose, which normally contains one molecule of water, loses this during the lyophilisation and can, as a result, play the role of a dehydrating agent in the lyophilised product.

These additional substances can be used individually or in mixtures. Harmoniously calculated proportions of these substances added to a solution of the material to be lyophilised make it possible to obtain a lyophilised product which is consistent, stable under normal ambient conditions, and entirely soluble and devoid of any toxicity (other than any toxicity of the medicament itself).

Variations in the amount of the lyophilization adjuvant make it possible to achieve any desired degree of hardness and solubility of the lyophilised product.

Medicaments of all kinds can be incorporated into mixtures to be lyophilized in accordance with the invention, e.g. water-soluble medicines, insoluble medicines dispersed as a colloidal suspension or emulsions, and also insoluble, undispersed medicines.

The lyophilised product obtained can be mechanically divided into pieces of well-defined shape and volume, which can be packed individually or in groups.

The pharmaceutical compositions obtained by the new process can be classified alongside effervescent, entirely soluble tablets while avoiding the use of large amounts of alkaline excipients, or alongside drinkable ampoules, having an advantage in cost price, or alongside any liquid form, having a definite advantage of lower volume and weight for a given dosage and showing great stability and excellent storage characteristics.

In the new process, the lyophilization adjuvant is added to the material to be lyophilised in the presence of a small amount of water, at ordinary temperature, and the resulting solution or paste is subsequently lyophilised in a manner known per se. If the mixture to be lyophilized is too liquid, because of the choice of the proportions of the constituents or for other reasons, and a separation takes place during mixing, the mixture is frozen with continuous stirring and when a pasty consistency has been achieved the mixture is spread on the previously cooled plates of the lyophilisation apparatus.

In one embodiment of the new process, the mixture to be lyophilised is converted into a foam and is stabilised with a block polymer of ethylene oxide, propylene oxide and ethylene glycol of molecular weight between 7500 and 8250, of the formula:

(where x, y, and z are integers) in which the (0 1-1 0) portion has a molecular weight of 1500 to 1800 and the (C H O) portion represents -90% by weight of the polymer. This embodiment is particularly advantageous for the preparation of a lyophilised composition containing vitamin C. It is all the more unexpected because it is known that vitamin C cannot be lyophilised by itself but melts, regardless of the lyophilisation conditions, forming a varnish on the cooled surfaces of the lyophilization apparatus, without a continuous solution, thereby resisting lyophilisation.

Another embodiment of the invention relates to the preparation of effervescent pharmaceutical compositions. Effervescent pharmaceutical compositions have hitherto been prepared by a dry method, by combining a medicament in the anhydrous form with an effervescent mixture consisting of two anhydrous powders, one containing non-toxic organic acid such as e.g. citric acid, tartaric acid, or ascorbic acid and the other containing a weak mineral base particularly (carbonate or bicarbonate) such as an alkali metal or alkaline earth metal carbonate or bicrbonate, especially neutral sodium carbonate or sodium bicarbonate, calcium carbonate, or magnesium carbonate. The mixture thus obtained is shaped into tablets and stored with exclusion of moisture. When introduced into water, it dissolves, causing an effervescence due to copious evolution of carbon dioxide.

The process of this invention for making such compositions is a wet process, in which the constituents of the effervescent mixture are added to the mixture to be lyophilised, at a temperature below 0 C. suflicient to prevent any reaction between the constituents of the effervescent mixture, and the paste obtained is subsequently the net dry weights of the products obtained after lyophilised. lyophilisatlon.

Such a process has many advantages. It makes it possi- TABLE I ble to obtain lyophilised compositions w i are @0111- Small containers No.1 No.2 No.3 No.4 No.5 pletely soluble, because no insoluble excipients used as Liver extract 9 4 4 4 lubricants for tablet making (talc, stearate and the like) Glycinep 60 60 are employed. Desiccation by lyophilisation yields dryer 33 ii g 1 g 1 products than those obtained by conventional drying proc- Water, m1 ..I 50 15 15 15 esses without reaching temperatures which present the weght afterlywmlisaflmrk" 61 61 6330 63-30 danger of altering any heat-labile active medicaments 0 present in the composition. The temperature and pressure conditions used during The invention is illustrated by the following examples. the lyophilisation are given in Table II below.

TABLE II Temperature and pressure conditions used during the lyophilisation process Time in hours 0 2 3 4 5 6 22 24 Temperature of the material in 0.... +20 +5 0 4 24 30 24 22 15 Pressure in mm. of H 700 700 700 700 2 10- 2x10- 1.3x10- 1.3 10- 1.3x10

Time in hours 25 27 28 29 30 31 44 46 Temperature of the material in 0.... 1 +22 +25 +27 +28 +30 +44 +37 Pressure in mm. of Hg 1.3 10- 10 10- 10- 10- 3x10- 3 10-= 3x10- EXAMPLE 1 After the lyophilisation, the small containers are In this example, the manufacture of a medicine based weighed at intervals WhlCh dunng the first six hours are on liver extract is described. The same process can also Initially closely Spaced, and the molstuffi uptdkt?S are be applied to other medicaments. pressed, in Table III below, in milligrams of water taken TABLE III Water uptake of the various samples as a function of time No. 4 No. 5 No. 1 No. 2 No. 3

Glycine plus Lactose plus Liver alone Glycine Lactose liver liver Milligrams 2.30 01 g. 01 g. 03.3 g. 03.3 g.

(mg) Percent (mg.) Percent (mg.) Percent (mg) Percent (mg.) Percent 1 Water uptake by the liver extract in the glycine (N0. 4-No. 2). 1 Water uptake by the liver extract in the lactose (No. 5-No. 3). 8 Weight of the lyophilised product.

The starting point is a commercially available liver up by the contents of the small containers, the adjacent extract for drinkable preparations, 1:25, in the form of column giving the percentage of water in the product.

a soft extract containing 82% of solids. The examination of the results shows that during the Small lyophilisation containers, of parallelepiped shape first hours the moisture uptake of the liver extract in and of size 5 cm. x 5 cm. x 3 cm., made of an aluminum lactose (No. 5) or in glycine (No. 4) is very slight relafoil of microns thickness, are used. The surface which is tive to (that of) the lyophilised extract (No. 1), because in Conta t With all i t s 5X5=25 cm. The small conthe 2.30 g. of dry extract only take up 11 mg. after 4 tainers, numbered 1 to 5, are filled as follows: hours in lactose 1 and 52 mg. after 4 hours in glycine while the lyophilised extract (No. 1) had taken up 131 1 Sohmom mg., representing 5.7% of water, as against 0.153% for Liver extract, 1:25 --g-- 4 the mixture of lactose-i-liver and 0.2% for the mixture Water ml T 50 of glycine+1iver.

No. 2Homogeneous paste obtained by triturating in a Thls shows that the very hygroscoplc Products are protected against a rapid moisture uptake, which allows mortfir' them to be handled without taking many precautions and Glycme g 60 furthermore their low water content ensures that they Gurn arable 1n powder form 1 store excellently. Furthermore, lactose has proved supe- Water ml 15 rior to glycine.

N 3 h Same paste as 2, in which the glycine is The measurements of the mechanical strength of the l d by lactose, lyoph1l1sed products were earned out with a needle pene- N 4 Same paste as 2 b i 4 f liver trometer usually employed for measuring the hardness extract dissolved in the 5 1 f water of tablets. An increasing force is applied to the material N 5 h same paste as 3 to which 4 g. f liver over a constant surface area and the force required for extract h b dd breakage or for penetration of the needle is measured.

Table I summarises the composition of the contents I l l I I 1 of the small contamers before lyoph1l1sat1on and gives 43:: iggifigifiig $31:

For the products No. 1 to No. 5 quoted above, the following hardnesses were found:

The process described in Example 1 is repeated, but replacing the gum arabic by each of the following excipients.

The experiments were carried out adding the amount of polymer indicated below to 250 g. of lactose or of glycine:

G. Polyethylene glycol, M.W.=20,000 15 Polyethylene glycol, M.W.=6,000 15' Polyvinylpyrrolidone Carboxymethylcellulose 2.5 Sodium alginate 1.25 Guaranate AC 110 1.25

All these experiments proved satisfactory and gave results of the same order as those mentioned in Example 1 above.

EXAMPLE 3 The process of Example 1 is repeated, but replacing the lactose and the glycine by other substances such as: glucose, sucrose and mannitol, either by themselves or mixed with the two preceding substances. The experiments carried out with or without gum arabic gave good results. Table IV below gives in grams the quantities used in the various experiments.

TABLE IV Experiment 1 2 3 4 5 Glyelne "-3: 100 Mannitnl 250 300 Sucr e 250 Glucose 250 250 Gun arabic..-.. 15 15 EXAMPLE 4 (1) lactose+glycine+gum arabic; (2) glycine+gum arabic; did not allow a dose of 0.05 g. of vitamin C to be exceeded, regardless of the technique employed to cause foaming.

However, on using the following mixture:

glycine+gum arabic+RC 102 (Pluoronic F68) in which the RC 102 (a block polymer of ethylene oxide, pro- 6 pylene oxide and ethylene glycol) serves as a foam stabiliser, it proved possible successfully to lyophilise doses of vitamin C of 0.100 g., 0.250 g. and 0.500 g.

TABLE V Formulations produced} Vitamin G, g 0. 0.250 0.500 Glycine, g 1.100 1. 100 1. 100 Gum arabic, g 0. 06 0.06 0. 06 RC 102 platelets, g 0.05 0.05 0.05 De-ionized water, rnl 0. 3 0. 3 0. 3 For one piece of approximate Weight, g.-- 1.31 1. 46 1. 71

EXAMPLE 5 This examples describes the preparation, by lyophilisation, of a medicine based on arginine acid aspartate in an effervescent form. The following two mixtures A and B are separately prepared in a mortar:

MD TURE A Sodium bicarbonate g 8 Arginine base 3 4,34 Sucrose g 6.66 Lactose 2 5 Water ml 1.5

MIXTURE B Citric acid g 5 Aspartic acid g 5.66 Sucrose g 7.34 Lactose 2 7 Water ml 1.5

The two mixtures A and B are separately cooled until they reach a temperature of -4 C. or below. A is then rapidly mixed with B while continuing cooling. The paste is spread as an approximately 1 cm. thick layer on metal plates and frozen at -20 C., and the material is lyophilised. The lyophilised product is then cut into pieces each weighing 5 g. Each piece contains 1 g. of arginine acid aspartate and dissolved very rapidly in water.

I claim:

1. Process for the preparation of a pharmaceutical composition of liver extract which comprises lyophilizing an aqueous mixture of 4 parts by weight of liver extract, 1 part of gum arabic or sodium alginate as a water soluble colloid, and 60 parts of at least one soluble, edible, crystallizable extender selected from the group consisting of lactose, glycine, sorbitol, mannitol, glucose and sucrose.

2. Process according to claim 1 wherein the aqueous mixture contains 15 parts of water, gum arabic is the water soluble colloid and glycine or lactose is the extender.

References Cited UNITED STATES PATENTS 2,908,614 10/ 1959 Muggleton et al. 424-89 SAM ROSEN, Primary Examiner US. Cl. X.R. 424361, 363 

